激光熔覆镍基金属陶瓷涂层的组织性能研究

Microstructures and Properties of Laser Clad Ni-based Metal-ceramics Layers

运用 5kWCO2 连续激光器在 16Mn钢表面激光熔覆镍基B4 C金属陶瓷层 (NB4 C)和镍基SiC金属陶瓷层(NSiC) ,研究了两种激光熔覆层的组织、结构、显微硬度及滑动磨损特性 ,并用激光熔覆镍基合金层 (Ni6 0 )进行了滑动磨损对比试验。结果表明 ,熔覆合金层显微组织由枝晶固溶体及其间细密的共晶组织组成 ,NB4 C熔覆层主要组成相为γ Ni,γ (Ni,Fe) ,(Cr,Fe) 7C3,CrB ,Ni3B ,Fe2 B ,Fe2 3(C ,B) 6 和B4 C等 ,NSiC熔覆层主要组成相为γ Ni,γ (Fe,Ni) ,(Cr,Fe) 7C3,Cr2 3C6 和 (Cr ,Si) 3Ni3Si等。三种激光熔覆层的显微硬度及耐滑动磨损性能由高到低的顺序为 :NB4 C→NSiC→Ni6 0。

Laser clad metal ceramics layers of Ni based B 4C(NB 4C) and Ni based SiC(NSiC) have been obtained on 16Mn steel substrate by means of 5 kW continuous wave CO 2 laser. Microstructure, phases, microhardness and sliding wear characteristics of the layers have been studied. Microhardness and sliding wear characteristics of laser clad Ni based alloy layer (Ni60) was also investigated under the same conditions as a contrast. The results show that the microstructure of laser clad layers consists of dendritic solid solution and the fine eutectic structure between the dendrites. NB 4C clad layer mainly consists of γ Ni,γ (Ni,Fe), (Cr,Fe) 7C 3, CrB, Ni 3B, Fe 2B, Fe 23 (C,B) 6 and B 4C. NSiC clad layer mainly consists of γ Ni,γ (Fe,Ni), (Cr,Fe) 7C 3, Cr 23 C 6 and (Cr,Si) 3Ni 3Si. Microhardness and sliding wear resistance of the three laser clad layers have an order from high to low: NB 4C→NSiC→Ni60.